T 2.109 Lack of, or inadequate, planning of the storage system

The selection and use of storage systems and storage networks requires careful planning, installation, and configuration in order to guarantee trouble-free operation. The possible threats resulting from insufficient planning are illustrated in the following.

• According to experience, the requirement for storage capacity in an organisation increases faster than expected. If newly installed storage systems are not equipped to handle the potential growth, it may quickly become necessary to purchase new systems or even redesign the entire storage infrastructure.

• The technology used for storage systems and storage networks offers the capability of attaining very high levels of availability. High-availability storage environments in particular require highly detailed planning to avoid possible errors. Redundant components are often used to help increase the level of availability of storage systems. However, if the function of the storage system or storage network depends on the function of a single component at some location, the entire availability of the system is at risk. Such components are referred to as SPOFs (single points of failure).

• The performance requirements for an application as well as the interoperability requirements regarding the existing software and hardware may make the use of specific products unavoidable. If these aspects are not taken into account at the appropriate time during the planning phase, the result may be expensive and inefficient corrections during the implementation phase, delays in usage, or even significant disruptions to operations.